1. Field of the Invention
The present invention relates to a device for driving two driving force transmission members relative to each other, using electrical energy.
2. Description of the Related Art
Various transmission systems are known as devices for driving two drive shafts relative to each other (for example, JP-2001-124163-A).
However, conventional transmission systems are able to transmit driving force in only one predetermined direction from one drive shaft to another drive shaft. Furthermore, in order to recover electrical power by so-called regeneration, it is necessary to provide a separate motor.